The invention relates to DC brush motors and, more particularly, to DC brush motors with output gearing suitable for automotive power widows and having integral electronics that allow for one touch up and one touch down with anti-pinch protection during one touch up movement of the window.
One touch up and one touch down window control systems with anti-pinch protection have been on the automotive market for some time. Conventionally, an obstruction (such as a finger or hand) in the path of the closing window can be sensed directly or indirectly. A direct sensor is typically in the form of a seal switch at the top of the window opening, or can be an optical transmitter/receiver that directly detects an obstruction in the window path. An indirect method of sensing an obstruction uses the effect of the obstruction on the motor speed (reduced speed) or motor current (increased current) to detect the obstruction. The direct sensing method typically results in lower pinch forces and some types of sensors (such as optical) result in no pinching.
Most windowlift platforms use separate electronics modules, or incorporate the one touch and anti-pinch windowlift functions in electronics modules that already contain other functions such as power seat controls, power mirror controls etc. The combining of functions may be an option on some high-end luxury vehicles, but speed signal outputs are required from the motors to these modules, and motor power leads from the modules to the motors, greatly increasing the complexity of the wiring harness.
Indirect obstruction sensing systems have the advantage of not requiring an external sensor, however, there are several disadvantages with this system. The software algorithm in an indirect system is quite sophisticated requiring a significant amount of memory, including non-volatile RAM, to implement. The additional memory, and higher clock speeds result in an expensive micro-controller. A ring magnet and hall sensors (for speed sensing) in the motor are also required. One of the biggest drawbacks for the automotive system designer, however, is the extensive calibration of the software algorithm to the platform""s door/window design. This slows down the development of the complete door system, and re-calibration of the software algorithm is required if any changes are made to the window, window regulator, seals, etc. after the system is calibrated. Another disadvantage of the indirect system is that the electronics module must xe2x80x9clearnxe2x80x9d the individual door when it is installed to create an initial force table for future comparison. This xe2x80x9clearningxe2x80x9d process requires an additional assembly step in the OEM final assembly plant, along with special equipment.
Thus, there is a need to provide a novel DC brush motor windowlift control system with integrated electronics providing one touch up and down with anti-pinch protection that has significant cost and development advantages over existing systems.
An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is achieved by providing a windowlift control system for controlling movement of a window of a vehicle. The system includes a DC bush motor constructed and arranged to cause movement of the window up and down, and electronics integral with the motor for controlling the motor to selectively move the window up and down. The electronics includes obstruction signal inputs for receiving signals from an obstruction sensor, associated with the window, that directly senses an obstruction in a travel path of the window. The electronics accept digital or analog obstruction signal inputs. The electronics further includes switch decoding inputs for signaling manual or one touch up or down operation to move the window in an express up or express down mode or manual up or manual down mode. During the one-touch up mode of operation, the electronics are constructed and arranged to cause the motor to stop and reverse the window should an obstruction be detected. The electronics disable the express up mode if the obstruction signal inputs indicate the sensor is not ready or malfunctioning.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.